Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description goes well beyond them: it discloses that the day rules are a custom and not in the classical texts used for validation, and explicitly instructs the agent to say so. That is a genuine limitation/authenticity caveat an agent must relay, plus input prerequisites (birth date and town).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the trigger scenario, then the return shape, then the caveat and requirements. Dense and mostly waste-free, though the long run-on sentence listing tarabala/chandrabala and the explicit 'say so' instruction make it longer than strictly necessary.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema exists, and the description fully covers what comes back: a 60-day range, each day's weekday, nakshatra, tithi, tarabala and chandrabala counts, favouring flags, and the vehicle-linked planet. Combined with the caveat and input requirements, an agent has everything needed to call and interpret it.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description's parameter-relevant content ('Needs birth date and town; town_now sets the time zone of the days') largely restates what the schema already says for town_now (

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource: computing auspicious days (muhurat) to buy a vehicle from birth details. The returned content (next 60 days with nakshatra, tithi, tarabala, chandrabala, vehicle planet) is distinctive enough to separate it from siblings like daily_panchang or festival_and_vrat_dates.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Opens with an explicit trigger ('Use this when someone asks for a good day or muhurat to buy a car, bike or other vehicle') and supplies three literal user phrasings, which is strong routing guidance. It does not name a sibling alternative or state when not to use it, so it stops short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.